Dating from the 1970's, chorus pedals are still some of the most popular effects pedals with guitarists. With a chorus pedal, the original signal is mixed with a slightly delayed and detuned version of the original signal. The result is a much "thicker" sound that can give a guitar a fuller sound, much like a 12 string guitar. The original (and still highly coveted) chorus pedal was the Boss CE-1 Chorus Ensemble. Andy Summers of The Police is known for his use of a clean, chorused sound. Chorus pedals are available in either analog or digital format, mono or stereo.